By default, Bugzilla does not search the list of RESOLVED bugs.
You can force it to do so by putting the upper-case word ALL in front of your search query, e.g.: ALL tdelibs
We recommend searching for bugs this way, as you may discover that your bug has already been resolved and fixed in a later release.
  Simple Search Advanced Search  

Find a specific bug by entering words that describe it. Bugzilla will search bug descriptions and comments for those words and return a list of matching bugs sorted by relevance.

For example, if the bug you are looking for is a browser crash when you go to a secure web site with an embedded Flash animation, you might search for "crash secure SSL flash".